This article describes a process for converting color RGB
(Red/Green/Blue) images to LMS (Long/Medium/Short) photoreceptor
activations. In an RGB image each triple represents phosphor
luminosity in a CRT (Cathode Ray Tube) screen. In an LMS triple
each value simulates a retina photoreceptor activation upon
viewing the RGB triple displayed on a CRT screen. The conversion
process requires the phosphor emission functions for a CRT monitor
and the sensitivity functions for the Long, Medium, and Short cone
photoreceptors. To calculate the final photoreceptor activity,
transform the RGB pixels with the CRT emission function, then
multiply the result with the photoreceptor sensitivity vector.